1. Field of the Invention
The present invention is concerned with a multiple-sheet fill assembly designed for use in crossflow or counterflow cooling towers in order to effectively disperse a hot fluid to be cooled during passage thereof through the tower. More particularly, it is concerned with such a fill structure wherein the respective sheets include a plurality of spaced, outwardly extending bodies thereon which serve as spacers and indexing units; these bodies are located on the sheets for partial telescopic interfitting with the bodies on adjacent sheets and in such manner that load-induced warpage and deflection of the sheets is minimized.
2. Description of the Prior Art
A wide variety of cooling tower fill structures have been proposed in the past. Generally speaking, the function of these assemblies is to evenly disperse hot water or other fluid as it descends from an overlying basin or the like, in order to maximize thermal interchange between the water and cross or counterflowing air currents passing through the tower.
U.S. Pat. No. 3,733,063 discloses a fill assembly made up of a plurality of upright, chevron-ribbed polyvinyl chloride sheets arranged in spaced, opposed relationship. Each sheet is provided with a plurality of outwardly extending, frustoconical spacer knobs which are designed to engage corresponding plateaus on adjacent fill sheets. The spacer knobs and plateaus on each sheet are arranged in pairs, and are laterally spaced apart.
Multiple-sheet fill structures of the type disclosed in U.S. Pat. No. 3,733,063 are particularly advantageous in that they can be constructed using relatively low cost synthetic resin materials and conventional vacuum forming techniques. This significantly lowers costs and maintenance problems, particularly as compared with prior splash-type fill assemblies employing metallic or wooden components largely constructed on-site.
Despite the many advantages of multiple-sheet synthetic resin fill assemblies, certain problems have been encountered in their use. For example, the non-aligned orientation of spacer knobs between adjacent sheets in the fill assembly tends to create force vectors which lead to warpage and deflection of the sheets, particularly under high water loadings. That is to say, the spacer knobs on adjacent sheets are generally offset both laterally and vertically from one another, and these offsets create torque vectors when a load is imposed on the fill; an accumulation of such vectors can cause the sheets to deflect or twist relative to each other. This can in turn cause undue pressure drops across the fill structure, with the result that cooling efficiency is lowered.
In addition, lack of positive interlock between respective fill sheets can allow the sheets to slide or shift relative to one another. Here again, this is an unwanted effect that can lead to deflection and distortion of the fill assembly, with concomitant efficiency losses.